Feed-water-regulating system



Oct. 7, 1930. J. M. BARRETT ,777, 33

FEED WATER REGULAT ING SYSTEM Filed May 4, 1925 5 Sheets-Sheet 1 gmxenfov Oct. 7, 1930. Y J. M. BARRETT 1,777,633

I FEED WATER REGULATING SYSTEM Filed May 4, 1925 3 Sheets-Sheet 2FIG.'-ZI ywmczw (1110: near 930- J. M. BARRETT 7 1,777,633

FEED WATER REGULA TI'NG SYSTEM Filed May 4', 1925 s Sheets-Sheet agwuanloz Fla-Z1 MGM a m wu m nw attorney! Patented Oct. 7, 1930 UNITEDSTATES PATENT emu:

JOSEPH M.,BARRETT, OF FOSTORIA, OHIO, ASSIGNOR TO THE SWABTWOU'ICOMPANY,-

OF CLEVELAND, OHIO, A CORPORATION OF OHIO FEED-WAT'ER-REGOLATING SYSTEMApplication filed May 4, 1925. Serial No. 27,785. i

., This invention is concerned with improvements in feed waterregulators of the continuously operated type. Such regulators areusuallyresponsive to changesin the water level of the boiler being fed, butchanges in the rate of water flow in the feed water line to the boilerare not entirely dependent upon variations in the boiler water level forchanges in the feed water pressure over the boiler pressure efl'ects, toa considerable extent, the rate of the feed water flow to the boilerwhen such devices are used. While the pressure in a feed water line maybe maintained at a constant excess relative to the i hoi ler pressure,nevertheless pressure changes in the boiler may continually take placewhen the steam demand on the boiler varies, for example, when the boilerrating is stepped up or down and such constant feed water excesspressure while being proper for normal rating may be inadequate forheavy over-rating. Hence it is apparent that the rate of feed waterflowto the boiler can not be absolutely controlled by the usual feed waterregulator and particularly when the pressure in the feed water line isgreatly in excess of the pressure inthe boiler thus causing anunbalanced steam delivery from the a boiler. If the boiler being fedhappens to be one of a battery servicing a common steam header, thishoiler'steam delivery will be changed, thus causing variation in thesteam pressure in the header, or the line being serviced; all due to thefactthatthe proper rate of evapoi. ration of the water in the boiler islacking as a eonseql'lence of the overfeedin'g of the boiler by the feedwater line. Adjusting thefiring or furnace conditions of the boiler willnot reach this deficiency as the time element invol ved is shorthut veryfrequent in the course of a days operation, and the entire balancedboiler en vi ronmcnt is upset, in that, the superheater may accumulatecondensate; there is a tendency to decrease the temperature'of centageof gases; a lowering of the feed water temperatm'e, etc. 7 All oftheforegoing deficiencies in boiler operation in the modern power. plantmay be directly traceable to irregularity of feed water flow to theboiler,

the stack and thus to cause a drop in peer and this irregularity iscaused primarily by varying excess feed water line pressures over boilerpressures.

fl he. general object of my invention therefo'i'e, is the provision of aboiler appliance which is directly responsive to pressure conditionsin'the boiler for regulating or main-' taining pressure in the feedwater line at a constant excess relative to the boiler pressure.

A more specific object of my invention is the provision of a pressurereducin ap paratus for the feed waterline of a boiler to serve as aprotective means, for a feed water regulator valve of a ressuregenerator system controllin the .eed water flow to the boiler and whichserves to maintain a constant difi'erence between the pressure in thefeed Water line and in the boiler.

Other objects of my invention will hereinafter become apparent from thefollowing description referring to-the accompanying drawingsillustrating a preferred form thereof. The essential characteristics aresummarized in the claims.

In the drawings, Fig. 1 is a side elevation of a boiler and feed Watersystem therefor including an electrically driven pump; Fig. 2 is anenlarged view of a feed water pressure regulating apparatus; Fig. 3 is'acrosssectional elevation of the same; Fi 4 is a cross-sectional viewtaken along the me 44 of Fig. Sand Fig. 5 is an enlarged frag-' in ageneral way in 'a patent to N. Copley on a feed water regulator, No.1,193,125 and issued August 1, 1916. Such a mechanism is usually mountedon the boiler to have the pressure generator thereof extend through theplane of the normal waterelevel of the boiler.

The feed water regu ator The heat exchange of the pressure generator ofsuch an appliance is not sufiiciently rapid or efficient-enough toafford refined regulation of the feed water flow of a high pressuremodern power plant boiler since no refined water regulatorvalve. InFig.1, I show the drum 10 of a water tube boiler connected to a headeror line 12, and to a source of water supply through a feed water line13. The feed water line 13 is fed by a pump 15 connected to a suctionline 16, the pump being driven by a turbine or motor 17. Connected inthe feed Water line is a feed water flow regulating valve 20 of thediaphragm type such as is disclosed in the Copley patent referred to andthis diaphragm valve is operated by pressure in a line 21 connected to apressure generator 22. The pressure generator 22 is disposed to stand orextend through the plane of the normal water level of the boiler drum 10and to surround a conduit 23 connected to the boiler drum above andbelow the. Water level thereof. Such a connection may be made to a watercolumn valve 25 above the water level and below the water level to asecond water column valve 27. Immediately adjacent the regulating valve20 I provide a pressure control valve 29 preferably of the diaphragmtype which is connected to a lower region of the drum 10 of the boilerby a conduit 30. This valve functions in a manner to be hereinafterdescribed, to maintain aconstant difference between the pressures in theboiler drum and the pressure in the feed water line to the point ofpassage through the feed water regulatorvalve 20, and as shown in Figs.2 and 3, is disposed in the feed water line between the valve 20 and thepump 15.

The pressure regulating valve 29 comprises a main valve body 31 having adiaphragm supporting extension 32 attached to a branch thereof, and theupper perimeter of the extension member 32 comprises a bearing orclamping surface for a diaphragm 33.

The nut 45 is'f-ormed to rest in a counterbore 32 of the extensionmember and thereby limit the downward deflection of the diaphragm andthe cap 34 serves to restrict the upward movement of the diaphragm. Thisdiaphragm is acted upon-by the. boiler pressure plus an excess pressurein the form-of an adjusted spring pressure on one side and by anopposing feed water pressure on the other side which is enclosed by aclosure or cap member 34 secured to the extension member in any suitablemanner preferably with sure exceeds the maximum boiler pressure.

The valve proper may comprise a removable double seat close fittingmember 36 to contact or seat upon outlets 37 removably supported by thevalve, body partition wall 28. The lower seat portion of the number 36may be of greater effective area than the upper so that the number 36 isurged downwardly b the feed water pressure, so that the valve Wi lassume an open position in the event of breakage of any of thecontrolling parts. The valve member 36 may be connected to a diaphragmactuated stem 40 by a hollow nut 42 which engages an enlarged head 43formed on the lower end of the stem. The upper end of the stem isthreaded as indicated at 44 to receive a flanged nut 45 contacting withthe under face of the diaphragm 33 and a flanged nut 47 engaging theupper face thereof. A. passageway 49 is formed in the extension member32 of sufiicient diameter topermit the feed water to pass through theextension member and exert pressureon the underface of the diaphragm 33.A conduit 30 extend: ing from the boiler drum to the valve mech-' anismis connected to the valve through a by-pass valve 50 mounted upon abranch 51 of a spring housing member 59 which encloses anexcess-pressure spring 54. member 59 is mounted upon the cap 34 in aleak-proof manner and is of sullicient strength to withstand thegreatest pressure which may be exerted at any time within the boilerdrum 10. The excess pressure spring 54 is supported between a collarmember 56. in engagement with the upper end of the valve stem 40,- andan adjustible collar 58 which is suitably slottedto engage ribs or ways55 formed on the interior wall of the member 53 and the collar member 58is in threaded engagement with an exce s pressure adjusting screw 60which has a shoulder 61 bearing against the upper wall of the springhousing member 53. A packing gland 64 is provided in the upper wall ofthe spring housing member to closely fit about the screw member shown. 4

I would suggest certain refinements in the pressure valve structuredescribed tending to insure constant and accurate performance andparticularly in the body structure of the valve whichsupports and housesthe diaphragm. For instance the shape of the inner face of the plate cap34 may be such that when the pressure in the boiler is unusually low,the major portion of the upper face of the diaphragm'will be supportedby the plate and the collar 47 and the contours of these two members maybe such that the diaphragm The and valve member. It will be seen thatby' under face of the diaphragm under adverse pressure conditions. 7

Also the connection between the stem and the valvemember 36 may be suchthat the cap nut 42will firmly join the stem and valve member. Theenlarged end of the valve Stem may be provided with a key portion 10 toengage in slot 42 formed in the upper threaded end of the valve member36 to prevent relative turning between the stem changing the members 32and 34 to support diaphragms of different diameters, a standard productmay be manufactured for an extensive range of pressure controls whilenecessitating only the dimensionalchange of but three of the elements ofthe mechanism.

I also find that the seating relation between the seats 37 and the,valve member 36 may be of the specific shape shown in Fig. 5 wherein theconiformed seats 36 are shown as having a substantially ring contact onthe annular coniform shoulders 37 of the sleeve members. This restrictedcontact permits the valve members to be urged into a close seating orclosing relation under a predominating high pressure in the pump line.

The by-pass valve is provlded with a valve stem 70 which controls a'passage 71 extending to the branch passage 72 of the spring housing andthis valveflstem 70 may be of the needle type to interrupt fluidpressure between the boiler drum and the spring side or upper side ofthe diaphragm. A second valve stem 74 is provided in the bypass valvewhich is adapted to close communication between -a by-pass conduit 73and the spring housing passageway 72; Thus in normal operatingcondition, communication between the boiler drum and the spring chamberabove the diaphragm is restricted to a small cross section by use of theneedle valve. I find this to be a factor on the side of safety,particularly in the event of a fracture of the diaphragm, for thisrestricted passage would then prevent any harmful flowof feed water tothe boiler drum through the diaphragm by wayof the by-pass and at thesame time would create a back pressure above the diaphragm which withthe aid of the pressure of the spring 54 would keep'the difi'erentialvalve open until the stem 74 could be moved to open position and thestem moved to closed position. Thus the prevailing pump pressure in thebranch passageway 39 of the valve body 31. may be exerted within thespring housing 53 and-consequently en the upper face of the diaphragm.Hence the valve may be rendered inoperative, when desired.

It will be seen. from the foregoing descri tion of this valve mechanism,that since t e position of the valve is ahead of the feed watcrregulator, the desired excess pressure may be obtainedby adjusting thescrew 62 to compress the spring 54 whereby there will be exerted on theupper face of the valve and within the spring housing 59, a pressurewhich is equal to the spring pressure plus the prevailing pressure inthe boiler drum 10 and there will be exerted on the underface of thedialihragm and through'the extension member 32, the pump pressureexerted on the feed water in the branch passageway 38, and the valvebody 31. When this latter pressure is greatly in excess of'the combinedpressures of the prevailing boiler pressure plus the spring pressure,the diaphragm 33 will be deflected upwardly thus carrying the valvemembers 36 to seating or near seating position relative to the valveslecvcs37. It will thus be seen, that even though the feed water levelin the l'oiler is below normal andthe pressure generator 22 hasgenerated sufficient pressure to completely open the feed water flowcontrol valve 20, and if there has been an extreme drop in the boilerpressure very little water will pass through the boiler until thepressure in the boiler increases, whereupon this increase in pressurewill cause a downward deflecting of the diaphragm 33 and thus open thepressure regulating valve to permit flow. of feed water through theregulating valve 20 at a pressure which is at the desired excess overthe pressure prevailing in the boiler. On the other hand if the waterlevel is sulficiently low to cause the valve 20 to be wide I open andthe pressure governor valve is partly-open, the water will be fed to theboiler at the desired excess pressure over the prevailing steam pressurein the boiler. Taking a practical example of boiler operation toillustrate one of the chief advantages to be found in the use of myinvention, I will first assume that a power plant having a battery oftenboilers is operating with a two feed water line, etc., will giveapproximately a twenty pound excess pressure in the feed water line atthe feed water regulator valve. This excess pressure, ofcourse is excessover the two hundred pound boiler header line pressure and not atwenty-pound excess pressureover the actual drum pressure. If there is atwo-hundred pound pressure in the header line, then there is. an excesspressure in each of the boilers of about two hundred and five poundswhen the boilers are operatin'g at their usual boiler rating. We wouldthen have only an .actual excess feed water pressure of fifteen poundsover the prevailmg drum pressure of the boiler.

Under the foregoing conditions, regula ,tion may be maintained, but ifwe assume that a condition arises calling for a one hundred per centincrease in the rating of say half of the boilers, there is anadditional excess pressure or five pound increase in the aresultingdecrease in excess drum pressure over line pressure, then the excesswater pressure in the feed line to these low rating op- .eratingboilers, would. be about eighteen pounds' In the latter boilers, therewould be a resulting increase of feed water flow with the resultingfurther lowering of their steaming ability and for a short period theywould merely function as Water heaters. The water level in the highrating operating boilers would drop due. to the increasing vaporationtherein and also due to the lowering of the excess water pressure overthe drum pressure.

It will be obvious that if pressure governorsare positioned in eachindividual feed water line in the respective boilers, that only suchpressures will prevail in the feed water line as will have a constantexcess relative to the prevailing pressure in the boiler being fedirrespective-of the regulating condition of the feed water regulatorbeing operated by a pressure generator responsive'only to prevailingwater level conditions in said boiler. It also will be obvious that afurther use of such a governor valve will be found where high excesswater pressures are to be carried at pumps, due to small feed waterlines- (incidental to high pressure practice) and friction losses insuch lines and in the lines on the other-side of the pump, namelyeconomizer i-riction losses, etc. Furthermore it will be apparent thatif the high excess pressures are carried at the feed water regulatorvalve and not reduced before reaching the valve, excess of wear resultsin the feed water regulator valve members and furthermore the slightestchange in feed water regulator valve operation efiects a change in waterflow, all out "of roportion to the actual requirements of the moment dueto. lngh velocity of the feed-water flow under high excess pressure.

1. In a boiler feed pipe, the combination of a, valve responsive tochanges in water level in the boiler, a fluid actuated valve disposedadjacent thereto and res onsi've' to chapges in-pressure dropthroug thefirst namedfiilve, excess pressure means associated with-the lattervalve,.means for thrptsaid cham r whereby the fluid pressure sothat theexcess pressure 7 means forces the latter valve open.

2. In a feed water regulating system a boiler, having a feed water pumpfor exerting pressure in the feed water line in excess of the maximumrated boiler pressure, the combination of a pressure reducing means inthe feed water line, comprising a diaphragm actuated valve, a feed Waterflow regulating device connected in the feed water line between theboiler and the diaphragm valve, said diaphragm actuated valve beingconnected in the line whereby the reduced pressure may be exerted uponone side of the diaphragm, a conduit connected to the boiler below thenormal water level thereof, a second conduit connected to the feed waterline between the pump and said valve, means connecting said conduits tothe valve wherefor by either boiler pressure or pump pressure by way ofaddition to the prevailing boiler' pressure, a predetermined excesspressure.

- 3. In a feed water regulating system for a boiler, having a feed waterpump adapted to maintain feed water pr'ilssurein' excess of the maximumboiler press re, the combination of a diaphragm operated pressurereducing valve in the feed water line, a feed water flow regulatingdevice connected in the feed Water" line between the boiler and saidvalve, a conduit connected to the boiler drum and to a chamber ad'acentthe diaphragm of said valve where y boiler pressure may be exerted upon.one side of the diaphragm, a conduit connected to the feed water linebetween the ump and said valve and leading to ump pressure may besubstituted for the oiler pressure upon said diaphragm, means includinga by-pass. valve to effect such substitutiom'excess pressure meansadapted to act in the same direction with regard to said diaphragm, andmeans afiordingcommunication between the other side of said diaphragmand the feed water line between said valv'evand said regulatinnr devicewhereby the pumppressure plus the excess. pressure may act "against theboiler feed water pressure so that said valve maybe held o ifn when suchsubstitution is i effected by the. y-pass valve.

4. In afeed water regulatlng systemffor a boiler pressure, thecombination ofja diaphragm operated valve in the feed waterline, a feewater flow regulating device connected side of said diaphragm, meansnacstablishing on the opposite side oi? said diaphragm fluid pressureequal to that between said valve and sald device, and a valve in saidlast named conduit lor cont-rolling the flow of fluid therethrough bymeans of which varying pressures in excess of boiler pressure may beestablished upon said diaphragm.

5. In a feed water regulating system, having a feed Water pump adaptedto maintain feed water pressure in excess of boiler pressure, thecombination of a diaphragm operated valve in the feed water line, a feedwater flow regulating device connected in the feed water line betweenthe boiler and said Valve, a conduit conncctedto the boiler drum and toa chamber adjacent the diaphragm of said valve whereby boiler pressuremay be exerted upon one side of the diaphragm, a second conduitconnected. to the feed water line between the pump and said valve andleading to said chamber whereby the pump pressure may be exerted uponsaid diaphragm, excess pressure means adapted to act upon and in thesame direction with regard to said diaphragm, means connecting theopposite side of said diaphragm with the feed water line between saidvalve and said device, and means for controlling the flow of fluidthrough at least said last married conduit. v

6. In a boiler feed pipe, the combination of an orifice, afluid actuatedvalve disposed'adjacent thereto and responsive to changes in pressuredrop through said orifice and urged toward closed position by the fluidpressure between said orifice. and said valve, excess pressure meansassociated with said valve, means for conducting actuating fluid to saidvalve from a point on the boiler sideofrsaid orifice, means forconducting actuating fluid to said valve from the feed water pipe aheadof said valve, and valve means associated with both said last namedconducting means for controlling the flow of fluid therein.

7. The combination of a boiler,a feed water pipe, an orifice in saidpipe, a feed water pump, a diaphragm actuated valve' positioned betweenthe orifice and thepump, means for establishing fluid pressure on oneside of said diaphragm equal to the pressure between said valve and saidorifice. meanslor conducting fluid to the opposite side of saiddiaphragm from a point on the boiler side of said ori'fice,'means forconducting fluid to the same side of said diaphragm from a point betweensaid valve and said pump, valve means associated with both said lastnamed means for controlling the flow of fluid therethrough and varyingthe pressure exerted upon the diaphragm.

8. The combinatlon according-to claim 7 including adjustable excesspressure means supplementing the force controlled by said valve means.i,

9. The combination of a boiler, 'a feed water pipe, an orifice in saidpipe, a feed atcr pump, a diaphragm actuated pressure controlling valvedisposed between said pump and said orifice, means connecting one sideof said diaphragm with the feed water line between said valve and saidorifice, means connecting the opposite side of said diaphragm to theboiler side of said orifice,

means connecting the same side of said diaphragm with the feedlinebetween the pump and said valve, and independently operable valve meansassociated with each of said last named means for controlling the flowof fluid therethrough and for varying the pressure exerted on saiddiaphragm. v

10. The combination of a boiler, a feed water pipe, an orifice in saidpipe, a feed water pump, a diaphragm actuated valve in said pipe betweensaid pump and said orifice, adjustable means tending to force said valveopen, means for establishing fluid pressure equal to the pressurebetween said valve and said orifice on saiddiaphragm tending to closesaid valve, a conduit leading to the opposite side of said diaphragm forestablishing boiler pressure thereon, a second conduit leading to thesame side of said diaphragm for establishing pump pressure thereon, andindependently operable valve means in each of saidconduits forincreasing or decreasing theiopenings through which fluidv may flow ineach of said conduits whereby the fluid pressure exerted tending to openthe diaphragm actuated valve is a function of the relationbetween theopen ings of said la'st named valve means.

'11. The combination of a boiler, a feed water pipe, an orifice in saidpipe, a feed water pump, a pressure actuable valve in said pipe betweensaid pump and said orifice having a part movable by and subjected tofluid pressures for varying the opening of said valve, means tending toforce said valve open, means for establishing fluid pressure equal tothe pressure between said valve and said orifice on said arttending toclose said valve. fluidconductmg means leading to the opposite side ofsaid part from a point on the boiler side of said orifice, a secondfluid conducting means leading to the same side of said part from apoint between said pump and said valve, and valve means in the latterof, said fluid conducting means for controlling tlie flow therethroughwhereby fluid pressure tending to equal pump" pressure may beestablished on said part.

ieo

movement of-fiuid through both of sai 12. In combination, a boiler,afeed water pipe, a fluid pressure actuated valve disposed in said feedwater pipe and having a part subjected to fluid pressures for movingbination of an orifice, a fluid pressure actu- I ated' valve disposedinsaid feed water pipe in advance of said orifice and having a partsubjected to fluid pressures for moving the valve, means forestablishing the pressure existing at the outlet side of said valveonone side of said part, a conduit for conducting fluid betweenthe otherside of said part and a point onthe boiler side of said orifice, aconduit for conducting fluid to the last named side of said part from apoint on the inlet side of said valve, and means for controlling themovement of fluid through said last named conduit.

14. In combination, a boiler, a'feed water pipe, a fluid pressureactuated valve disposed in said feed water pipe and havinga partsubjected to fluid pressures for moving the valve, means for establishinthe pressure existing at the outlet side 0 said valve on one side ofsaid part, a conduit for conducting fluid between the other side of saidpart and a point on 'the boiler side of said valve, a conduit forconductin fluid to' the last named side of said part rom apoint on theinlet side of said valve and means for controlling the movement of fluidthrough both of said conduits.

15. In a boiler feed water pipe, the combination of an orifice, a fluidpressure actuated valve disposed in said feed water plpe in advance ofsaid orifice and having a part subjected to. fluid pressures for movingthe valve, means for establishing the pressure existing at the outletside of-saidvalve on one side of said part, a conduit for .conductmgfluid between the other side of said art and a point on the boiler sideof said or' ce', a conduit for conducting fluid to the last named sideof said part from a point on the inlet side of said valve and means forCOIltlOllilg the 60117 duits.

16. In a boiler feed pipe, the combination of an orifice, a fluidactuated valve movable in response to changes in pressure drop acrowsaid orifice and urged toward closed position by the fluid pressurebetween said orifice and said valve, excess pressure means associatedwith said valve,- means for conducting actuatvalve tending to open'it,means for conducting actuating fluid to said valve from a point on theboiler side of said orifice, and means apart from said excess pressuremeans for positively forcing said valve to open position.

18. The combination of a boiler, a feed water pipe, an orifice in saidpipe, a feed water pump, a pressure actuable valve in said pipe betweensaid pump and said orifice having a part movable by and subjected tofluid pressures for varying the opening of said valves, means tending toforce said valve open, means for establishing fluid pressure equal tothe pressure between said valve and said orifice on said part tending toclose said valve, fluid conducting means leading to the opposite side ofsaid part from a point on the boiler side of said orifice, and means forexerting a force on the last named side of'said part to force and holdsaid valve in open position.

19. The combination ofa boiler, a feed i water pipe, an orifice in saidpipe, a feed water pump, a pressure actuable valve in said pipe betweensaid pump and said orifice having a part movable by and subjected tofluidpressures for varying the opening of said valve, means exerting arelatively constant force tending to open said valve, means forestablishing fluid pressure e ual to the pressure between said valve ansaid orifice on saidpart' tending to close said valve, fluid conductingmeans leading to the opposite side of said part from a point on theboiler side of said orifice for establishing fluid pres- .sure on saidpart tending to open said valve,

and means for forcing and holding said valve in an" extreme position ofits travel.

In testimony whereof, I hereunto afiix my signature. v

JOSEPH M. BARRETT.

